My diabetic dad responded to the vaccine in a similar manner. We spent one scary day in the hospital. After changing his pills to insulin shots (temporarily for a month), he started getting well again.
Asking as some people close to me are diabetic and will be getting their shots soon. Thanks a lot
https://www.reddit.com/r/diabetes/search?q=vaccine+blood+sug...
https://medalerts.org/vaersdb/findfield.php?TABLE=ON&GROUP1=...
Edit: I think I must share his medical history too:
He is 65.
2007: diabetes
2018: multiple myeloma
2019: 6 months of kemo
2020: bone marrow transplant
2021: cancer is currently dormant, 2 shots of Sinovac in 30 days